1. Field of the Invention
The present invention generally relates to a radio telephone system within a vehicle, and in particular to a radio telephone system that can change the operation mode of a radio telephone terminal.
2. Description of the Related Art
A car-mounted telephone system having a function of switching its operation mode between a driving mode and a stop mode has been disclosed in Japanese Patent Unexamined Publication No. 4-192949. This conventional telephone system is provided with an ignition key detector and a phone-answering/recording machine. The phone-answering/recording machine is automatically activated or inactivated depending on a detection result of the ignition key detector. For example, when an ignition key is turned on, the telephone system is set to a normal mode where communication is made available. When the ignition key is turned off, the telephone system is automatically set to a phone-answering/recording mode.
As another conventional example, an in-car adapter for mobile telephone has been disclosed in Japanese Patent Unexamined Publication No. 4-287740. This system can ensure the continuity of conversation even if the ignition key is turned off during conversation.
According to the above telephone systems, however, the telephone handset is mounted in the car or the mobile telephone is directly connected to the adapter mounted in the car. Therefore, the convenience of portability in a mobile telephone terminal is extremely reduced.
Further, the use of mobile telephone while driving a car frequently causes a traffic accident. To prevent such a traffic accident, a hands-free telephone set has been commercially available. Various measures against traffic accidents caused by the use of mobile telephone while driving a car are needed more and more.
An object of the present invention is to provide an in-car radio telephone system which can control the operation mode of a radio telephone terminal without reducing the convenience of portability of the radio telephone.
Another of the present invention is to provide a radio telephone system which can change the operation mode of a radio telephone depending on the operation state of a vehicle.
Still another of the present invention is to provide a radio telephone which can change in operation mode without reducing the convenience of portability thereof.
According to an aspect of the present invention, a radio telephone system for use in a vehicle is comprised of an accessory mounted in the vehicle and a radio telephone that is separated from the accessory. The accessory includes a detector for detecting an operation state of the vehicle and a wireless transmitter for transmitting a mode switch signal indicating the operation state to the radio telephone. The radio telephone includes a radio transceiver for telephone communication, a wireless receiver for receiving the mode switch signal from the accessory, and a controller for changing an operation mode of the radio telephone depending on the mode switch signal.
The detector may detect an on/off state of an ignition key of the vehicle. When the ignition key is in the on state, the wireless transmitter transmits the mode switch signal indicating a driving state and, when the ignition key is in the off state, and wireless transmitter transmits the mode switch signal indicating a stop state.
The detector may detect a speed of the vehicle. The speed of the vehicle is not lower than a predetermined speed, the wireless transmitter transmits the mode switch signal indicating a driving state and, when the speed of the vehicle is lower than the predetermined speed, the wireless transmitter transmits the mode switch signal indicating a stop state.
The controller may select one of two predetermined modes as the operation mode of the radio telephone depending on the mode switch signal. The two predetermined modes are selected from a communication mode that makes a normal telephone function active, a phone-answering mode that makes an automatic answering function active, and a suspending mode that makes both the normal telephone function and the automatic answering function inactive.
Further, the two predetermined modes consists of a first mode and a second mode, wherein the first mode is selected when the mode switch signal indicating the driving state is received, and the second mode is selected when the mode switch signal indicating the stop state is received. Preferably, the first mode is one selected from the phone-answering mode and the suspending mode.
According to another aspect of the present invention, the accessory includes a detector for detecting an operation state of the vehicle, a wireless transceiver for transmitting a mode switch signal indicating the operation state to the radio telephone and receiving a mode switch completion signal from the radio telephone, and an accessory controller determining whether the mode switch completion signal is received from the radio telephone after the mode switch signal has been transmitted to the radio telephone and stopping the wireless transceiver transmitting the mode switch signal unless the mode switch completion signal is received from the radio telephone. The radio telephone includes a radio transceiver for telephone communication, a wireless transceiver for receiving the more switch signal from the accessory and transmitting the mode switch completion signal to the accessory, and a radio telephone controller for changing an operation mode of the radio telephone depending on the mode switch signal before causing the wireless transceiver to transmit the mode switch completion signal to the accessory.
According to the present invention, a radio telephone is separated from an accessory mounted in a vehicle, wherein the accessory transmits a mode switch signal to the radio telephone when a change of an operation state of the vehicle is detected. The radio telephone includes a radio transceiver for telephone communication, a wireless receiver for receiving the mode switch signal from the accessory, and a controller for changing an operation mode of the radio telephone depending on the mode switch signal.